Guardian: Europe’s leaders know where they want to be when it comes to tackling global warming. The problem is they don’t know how to get there. President Nicolas Sarkozy of France, running a two-day summit of EU leaders which ended in Brussels today, hoped to propel Europe towards a December deal. Instead, he has set the stage for a Christmas showdown. It’s the 20/20/20 vision, as they say in Brussels when referring to the aim and the deadline. The idea, according to the programme …